Pumping system for the injection of measured quantities of fluid into a fluid stream

ABSTRACT

A pump system for the selected injection of one or more fluids is disclosed where the system generally includes a flow meter including a means to translate the flow rate through the meter to one or more pumps coupled to the meter such that upon a selected introduction of fluid flow through the meter a selected amount of fluid is pumped through the one or more pumps.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of applicant's application Ser. No.09/327,201, now U.S. Pat. No. 6,357,466, as filed on Jun. 7, 1999. Thedisclosure of the parent application is herein incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to an apparatus and method formetering fluid. More particularly, the present invention is directed toan apparatus to injected a predetermined amount of a liquid into a fluidstream and methods for its use.

2. Description of the Prior Art

Several devices have been developed for injecting predeterminedquantities of liquid additives into a liquid flow stream for suchapplications as adding medication to drinking water with additives suchas chlorine or iodine and adding fertilizer concentrate to irrigationwater. An exemplary device which is powered by the liquid stream towhich the additive is being injected is described in U.S. Pat. Nos.3,937,241 and 4,060,351 as issued to Philippe Cloup. In the apparatusdescribed in the Cloup patents, the additive or adjuvant is injectedinto the main fluid stream within a piston chamber of a hydraulic motorwhich drives the additive injection pump.

The architecture for this metering pump, however, is disadvantageouswhen the additive is a corrosive fluid such as chlorine, fertilizer orother chemically active substance. Accordingly, it is desirable to beable to inject the additive into the liquid stream at a point downstreamof the motor which is powering the additive pump to avoid problemsassociated with the corrosive action of the additive.

To accomplish this objective, a number of fluid pumps have been designedwhich inject the additive into the primary fluid stream where theprimary fluid provides the motive fluid for activating the additiveinjection pump. Such a device is described for example in applicantsU.S. Pat. No. 4,558,715 as issued to Walton.

While overcoming many of the disadvantages of prior fluid injectionsystem, the apparatus described in the Walton patent involves a numberof components which are subject to wear and subsequent failure. Elasticor elastomeric biasing components necessary in a piston drive pump areparticularly prone to fatigue and failure. Moreover, the use of a pistonand its auxiliary components enhance production and manufacturing costs.

SUMMARY OF THE INVENTION

The present invention addresses the above and other disadvantages ofprior art metering pumps by providing a system which includes a minimumof moving components in a robust design to selectively inject a secondand/or a third fluid in a fluid stream, where the second and third fluidconstitute a predetermined percentage of the total mixture.

In one embodiment, the present invention is directed to an apparatus forgenerating a mixture of a first fluid and measured quantities of asecond fluid, wherein the second fluid constitutes a predeterminedpercentage of the ultimate mixture. In one aspect, the system includes aflow meter which includes an inlet in fluid communication with the firstfluid, a fluid outlet and first and second gears positioned between theoutlet and inlet. The gears of the flow meter are meshed together andcounter rotate relative to each other when the first fluid, e.g. water,is directed through the inlet to the outlet.

A shaft is connected coaxially to the first gear and the first gear of acavity gear pump. The cavity gear pump includes a first and a secondgear disposed in a housing and includes an inlet and an outlet. Each ofthe first and second gears define a transverse cavity or pocket toreceive and pump a liquid from the inlet to the outlet. Because thefirst gear of the cavity pump is connected through the shaft to thefirst gear of the flow meter, a predetermined amount of the second fluidis pumped through the outlet of the cavity pump when a predeterminedamount of the first fluid is directed through the flow meter.

In another aspect of the invention, a second shaft is coaxially coupledto the second gear of the flow meter and a first gear of a second cavitygear pump which also includes an inlet and an outlet where the inlet iscoupled to a reservoir of a third fluid and the outlet is coupled to thefluid stream. In such a fashion, a third fluid may be selectivelymetered and introduced into the fluid stream.

The present invention offers a number of advantages over prior artmetering pumps. One such advantage is a robust design which requires aminimum of moving components. In such a fashion, the apparatus isrelatively inexpensive to manufacture and maintain.

Another advantage of the present invention is its lack of dependance onelastic biasing components to accomplish the metering process.

Another advantage is the ability to avoid contamination of the freshwater supply by introducing the metered additive concurrently with themetered water into the treatment pool. In such a fashion, inadvertentbackflow will not result in a contamination of the water supply.

Yet other advantages include quiet operation, a compact size whencompared to competitive devices and a low pressure loss across the inletand outlet of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective, partially phantom view of oneembodiment of the present invention operative for the injection of ametered, second fluid.

FIG. 1A illustrates a detail, perspective view of the embodimentillustrated in FIG. 1.

FIG. 2 illustrates a side, cross sectional view of the embodimentillustrated in FIG. 1.

FIG. 3 illustrates a perspective view of a second embodiment of thepresent invention operative for the injection of a second and a fluid.

FIG. 4 illustrates a top view of the embodiment illustrated in FIG. 3.

FIG. 5 illustrates a side, cross sectional view of a third embodiment ofthe present invention.

FIG. 6 illustrates a side, cross sectional view of a helical gear pump.

FIG. 7 illustrates an exploded view of the helical pump illustrated inFIG. 6.

FIG. 8 illustrates a perspective, assembly view of a fourth embodimentof the invention utilizing an impeller.

FIG. 9 illustrates a cross section of an impeller as it may be used withthe embodiment of FIG. 8.

FIG. 10 illustrates yet another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the pumping system of the present invention may beseen reference to FIGS. 1 and 1A.

As illustrated, the pumping system 2 includes a flow meter 4 to which ismounted a metering pump 40 where flow meter 4 includes a housing 13, afluid inlet port 18 and a fluid outlet 17. As intended by the presentinvention, flow meter broadly means a device which has at least onemovable element, and the movable element can be moved when fluid isdirected through the device. In the embodiment shown in FIGS. 1-1A, theflow meter 4 is a gear-type flow meter, as more fully described below.

In the illustrated embodiment, the fluid inlet port 18 of the flow meter4 is connected to a fluid conduit 20. More specifically, in onepresently preferred embodiment, conduit 20 includes an angular threadedconnector 18 which can rotate relative to said conduit, and theconnector can be engaged with threads that are formed on inlet port 18.In turn, conduit 20 is situated in fluid communication with a watersupply or other source of fluid 19. It is to be understood that conduit20 can be connected to a water supply by any suitable means known in theart, e.g., by connecting conduit 20 to a fitting or nozzle that is inturn in fluid communication with a water supply.

The housing 13 of flow meter 4 comprises a top wall 17, a bottom wall 11and a side wall 14 where each of the aforereferenced elements areadapted to be combined to form a substantially fluid tight unit.Typically, housing 13 includes some sort of access means, e.g., anaccess plate (not shown), to allow for inspection, repair andreplacement of the internal components of flow meter 4.

In accordance with the present invention, flow meter 4 includes one ormore rotational elements which, in the embodiment shown in FIGS. 1-2,include a first gear 24 and a second gear 25 which rotate when thepressurized first fluid passes from the inlet 18 port to the outlet port17.

By reference to FIG. 2, gears 24 and 25 are disposed within an internalcavity 23 defined by housing 13. In some embodiments, gears 24 and 25may be provided with magnetic inserts (not shown). The introduction offluid through inlet 18 rotates gears 24 and 25, thereby moving inserts92 past a point on the housing 13, which contains means to detect therotation of said insert 92. The frequency of this rotation may then bemonitored to determine a flow rate.

In the embodiment illustrated in FIGS. 1-2, metering pump 40 includes ahousing 41 defining an internal cavity 49 in which are disposed a pairof intermeshing, counter rotating rotors 44 and 46. Housing 41 includesa sidewall 43, a bottom wall 45 and a top wall 47, the combinationadapted to be sealed to form a fluid tight compartment defining an inlet50 and an outlet 52, where inlet 50 is disposed in fluid communicationwith a reservoir 51 of a second fluid via conduit 55.

In some embodiments, the bottom wall 45 of pump 40 may compromise thetop wall 17 of flow meter 4. In such a fashion, economy of constructionmay be observed.

By reference to FIGS. 1A, 6 and 7, it is desired that rotors 44 and 46define a tooth pattern which promotes a maximum amount of fluid flowfrom inlet 50 to outlet 52. It may be desirable to utilize a helicaltooth pattern such as that disclosed in U.S. Pat. No. 5,415,041, thedisclosure of which is herein incorporated by reference. Other toothpatterns, however, are also contemplated within the spirit of theinvention. For example, it may also be desirable to adopt a herringboneor straight tooth pattern to advance the objects of the invention.

By reference to FIGS. 6 and 7, rotors 44 and 46 are preferably providedwith a system of bearings to enhance smoother and low drag operation.Top wall 47 preferably comprises a cover to close the cavity 49 byfitting on a machined face of said housing 41 which is bolted in placewith bolts 42 which extend through openings 63 of cover 48 into alignedreceivers 65 in housing 41.

The buildup of deposits, e.g., calcium and precipitants from theadditive solution, is a major cause for premature failure of cavity gearpumping systems. In some applications therefore, it may be desirable toutilize a metering pump housing which defines a close tolerance betweenrotors 44 and 46 and the pump outlet 52, the walls defining cavity 49and the pump inlet 50. In such a fashion, any deposits collecting aboutthe inlet 50 or outlet 52 are continuously sheered off by rotors 44 and46 during the operation of pump 40.

In the embodiment illustrated in FIGS. 1 and 2, a connecting element 30,e.g., a spline, is coupled to first rotor 25 of flow meter 4 and extendsthrough flow meter housing 13 into operative engagement with the rotor44 of pump 40. In such a fashion, the rotation of gear 24 as induced bythe flow of the first fluid from the inlet 18 to outlet 17 rotates thefirst rotor 44 and hence second rotor 46. The counter rotation of rotors44 and 46 create a partial vacuum in housing 41, thereby inducing fluidflow of the second fluid from reservoir 51 through conduit 55 into inlet50 and ultimately through outlet 52.

The coupling of rotor 24 to rotor 44 of pump 40 allows for the meteredinput of the additive second fluid based on the flow valve of the fluidas dictated by the rotation of rotors 24 and 25. The proportions of theadditive fluid may be varied based upon the ratio of the size of rotors24 and 25 vis-a-vis rotors 44 and 46. Alternatively, spline 30 may beformed to include a manually adjustable gear down assembly (not shown)to allow the ratio of the additive fluid to be altered.

By reference to FIG. 1A and 2, in one aspect of the invention, pump 40may be provided with priming means which comprises a piston 86 slidablysituated in a bore 89 which is disposed in fluid communication withcavity 23 of flow meter 4 via access bore 95. Reciprocation of piston 86in bore 89 allows the first fluid, e.g. water, to pass through bore 89into cavity 23, thereby priming pump 40.

It is contemplated that it may be desirable in some situations tointroduce the additive fluid downstream of flow meter 4. In otherapplications, however, the pump outlet 52 may be disposed upstream ofmeter 4 or concomitant with flow meter outlet 17.

A second embodiment of the present invention may been seen by referenceto FIGS. 3-4 in which is illustrated a flow meter 100 of the generalconfiguration as described above in relation to the embodiment of FIGS.1 and 2, where such flow meter 100 includes a first 102 and second 104rotational element rotatingly disposed within an internal cavity 106defined within a housing 105 which also includes an inlet 108 and anoutlet 110. Inlet 108 is disposed in fluid communication with a firstsource of fluid, e.g., water, through a conventional conduit 113 orother similar fluid flow member. Outlet 110 is likewise coupled to aconduit 115, as illustrated.

A first metering pump 140 and a second metering pump 160 are joined toflow meter 100 in a similar manner to that described in relation to theembodiment of FIGS. 1 and 2. In this connection, one or both of first140 and second pumps 160 may share a common wall with flow meter 100.Alternatively, either or both of first and second pumps may be formedintegrally with flow meter in a common housing with means provided forthe separation of fluid flow. Still alternatively, first or second pumpsmay be raised or separated from flow meter 100 as long as means areprovided for the translation of the rotation of the rotationalelement(s) of flow meter 100 to said first and second pumps. This laterarrangement may be helpful, for example, where it is desirable to removeone or more metering pumps from exposure from the heat of the primaryfluid passing through flow meter 100. Such an arrangement, may also behelpful when there exists space and design concerns. This design alsoprovides an air gap to separate the source of drive water and thechemical being pumped.

Each of metering pumps 140 and 160 include, in the example of the firstpump 140, a housing 122 defining an internal cavity 123 and an inlet 125and an outlet 126, where said inlet 125 is coupled to a second source offluid 137 by a conduit 129. In this embodiment, at least one rotationalelement 131 is rotatably disposed in cavity 123 such that the rotationof said element 131 induces fluid flow through inlet 125 and outlet 126.

A connecting element 120, e.g., a spline, is coupled to one or both ofrotational elements 102 and 104 and to at least one of the rotorelements disposed in both first and second pumps 140 and 160,respectively. In such a fashion, the flow of fluid from inlet 108 tooutlet 110 of flow meter 100 rotates first and second rotationalelements 102 and 104 and at least one of the rotors disposed in each offirst and second pumps 140 and 160. As described above in relation toprior embodiments, the rotation of rotors in pumps 140 and 160 inducesfluid flow from each of reservoirs 137 and 143 through respective fluidinlets 148 and 129 and through outlets 126 and 132 and ultimatelythrough valve 91 and common flow passage 80. In the embodimentillustrated in FIG. 4, additive second and third fluids are introducedto the fluid stream through housing 105. Alternatively, one or more ofthe additive fluids may be introduced in the outflow conduit 115 asillustrated in FIG. 3.

In some applications, it may be desirable to include means to divert atleast a portion of an additive fluid back to the fluid reservoir. Suchreticulation may be important, for example, when the additive fluid isprone to settling. By reference to FIG. 4, a valve 91 may be disposed inoutlet conduit 80 such that upon partial opening of valve 91 a portionof the additive fluid is diverted back to the fluid reservoir.

Yet another embodiment of the present invention may be seen by referenceto FIG. 5 in which is illustrated a flow meter 150, a first pump 170 anda second pump 190. Flow meter 150 is configured in much the same fashionas described above in relation to other embodiments and may adopt avariety of configurations. It is desired, however, that meter 150include a fluid tight housing 151 defining an inlet and an outlet, whereat least one rotor element 155 is disposed therebetween. Similarly,pumps 170 and 190 may also adopt a number of configurations involvingthe use of at least rotational element which is coupled to element 155.In this connection, it is contemplated that one or both of pumps 170 and190 may incorporate counter rotating helical gears of the typeillustrated in FIGS. 6 and 7 or may alternatively utilize a single rotorformed in a cavity disposed in a housing. In each case, however, it isdesirable that the rotor element of pumps 170 and 190 be rotationallycoupled to at least one of the rotational elements of the flow meter150.

In the illustrated embodiment, pumps 170 and 190 are arranged in avertical or “stacked” relationship with respect to one another as toshare a common interconnecting element or spline 175. In such a fashion,the rotation of the rotational element of flow meter 150 results in therotation of rotors in each of pumps 170 and 190 to include the meteredflow of second or third fluids as described above. As set forth above,the ratio of the injection of the second and first fluids may bedetermined as a function of the ratio of the respective gear sizebetween each of pumps 170 and 190 to flow meter 150. Alternatively, acompound spline 175 may be employed which allows for the selectiveadjustment of the rotation of one or both of pumps 170 and 190 vis-a-vismetering pump 150.

The immediately aforedescribed embodiment may be desirable due to spaceconstraints or design limitations.

Yet another embodiment of the invention may be seen by reference toFIGS. 8 and 9 in which is illustrated a flow meter 200 which includes ahousing 202, a fluid inlet port 204 and a fluid outlet 206, as describedpreviously in relation to other embodiments. Housing 202 itselfcomprises a top wall 211, a bottom wall 209 and a side wall 202.Consistent with prior embodiments, flow meter 200 includes one or morerotational elements 214 (as shown in phantom) which rotate about shaftsand include an extended spline 215 which extends outside housing 202. Inthe illustrated embodiment, spline 215 includes a flat 216 to aid inengaging pump 230, as will be described below.

By reference to FIGS. 8-9, pump 230 includes a housing 232 which isgenerally circular in configuration and which defines a substantiallycircular bore 239, a fluid inlet 240 and an outlet 242. Bore 239 isreceivable to an impeller 234 which is adapted to rotate about a hub239. It is contemplated that hub 239 includes a fixed shaft engageablewith spline 215 so as to transfer the rotation of spline to impeller 234so as to pull fluid from inlet 240 through outlet 242.

As illustrated, impeller 234 is eccentrically disposed in bore 239,which eccentricity is adjustable depending on desired flow rates.Housing 232 includes an adjustment flange 260 which includes a pivotaperture 262 about which housing 232 may be pivoted in a plane coplanarwith the plane described by housing top 211. The pivot of housing 232serves to distort the shape of impeller 234 so as to increase ordecrease the quantity of fluid moved through said pump 230. In thisconnection, impeller 234 is preferably made from a pliable compound,e.g. rubber, which allows resilient deformation. Impeller 234 itselfdefines a number of fins which will be familiar to those skilled in theart.

It is contemplated that the aforedescribed adjustment to impeller 234may be made manually and gauged about gradations scored on top 207.Alternately, a flow gauge (not shown) may be situated in the outflowline (not shown) and manual adjustments made from this flow gauge. Stillalternately, pump 230 may be remotely adjusted, e.g. by a stepper motor,to achieve a desired and preprogrammed flow rate. In the instance ofmanual adjustment, pump housing 232 may be secured to meter housing 202about a particular orientation by a screw 250, as illustrated.

Fluid metered through pump 230 need not be necessarily introduced intoflow meter 200, to outlet 206 or outlet line 213 immediately downstreamfrom outlet 206. Instead, the metered additive may be carried in aseparate line 243 which may parallel water outlet line 209, where lines209 and 243 coterminate at a given point, e.g., the mixing pool. In sucha fashion, inadvertent backflow will not result in a contamination ofthe water supply.

Still another embodiment of the invention may be seen by reference toFIG. 10 in which is illustrated a flow meter 300 defining a housing 302and at least one interior metering element which is rotated about theintroduction of fluid through meter 300 in a manner consistent with thatdescribed above. In the illustrated embodiment, at least one of therotatable elements includes a spline 304 which extends beyond housing302 and is coupled to a cam wheel 307 which in turn is coupled to acrank 309 in a manner familiar to those skilled in the art. Crank 309 isin turn coupled to a metering pump 312 of a design generally disclosedand claimed in U.S. Pat. No. 4,558,715.

In such a fashion, the introduction of water into meter 300 turns atleast one rotatable element which in turn acts upon crank 309 and pump312 to induce a metered flow of fluid, e.g. medication or chemicals. Theamount of fluid introduced through pump 312 may be adjusted in aconventional fashion as disclosed in Applicant's prior patents, U.S.Pat. Nos. 4,809,731 and 4,558,715.

Although particular detailed embodiments of the apparatus and methodhave been described herein, it should be understood that the inventionis not restricted to the details of the preferred embodiment. Manychanges in design, composition, configuration and dimensions arepossible without departing from the spirit and scope of the instantinvention.

What is claimed is:
 1. A system for generating a mixture of a firstfluid and a second fluid, wherein the second fluid constitutes apredetermined percentage of the ultimate mixture, said systemcomprising: a flow meter having an inlet in fluid communication with thefirst fluid, an outlet, and at least one rotatable element positionedbetween the inlet and the outlet, wherein said rotatable element rotatesabout an axis when the first fluid is directed through the inlet to theoutlet, said element disposed in a housing defining top, bottom and sidewalls; a shaft coupled to the rotatable element; a first pump includingat least one rotatable element mounted within a second housing defininga top, bottom and side walls where said bottom wall is common to the topwall of the first housing, said first pump disposed between an inlet fora second fluid and an outlet, where said rotatable element is operablycoupled to said shaft such that a predetermined amount of the secondfluid is pumped through the outlet of the first pump when apredetermined amount of the first fluid is directed through the inlet ofthe flow meter to the outlet of the flow meter where the first pumpoutlet is concomitant with the outlet of the flow meter; and a shaftconnected to the rotatable element of the flow meter and a second pumpincluding a first and second gear mounted within a second housingbetween an inlet for a third fluid and an outlet, where said first gearof said second pump is coaxially coupled to said shaft such that apredetermined amount of the third fluid is pumped through the outlet ofthe third pump when a predetermined amount of the first fluid isdirected through the inlet of the flow meter to the outlet of the flowmeter.
 2. A dosing apparatus for mixing a first and other fluids in apredetermined, volumetric relationship comprising: a flow measuringcomponent having an inlet in fluid communication with the first fluidand an outlet, where said flow measuring component further includesmeans which rotate at a selected number of revolutions when apredetermined amount of fluid is directed from the inlet to the outlet;means to translate the rotation of said component; a second fluiddisposed in fluid communication with the inlet of a fluid pump whichincludes a housing defining a fluid inlet and a fluid outlet, where saidpump is coupled to said translation means such that the rotation of therotational means actuates said fluid pump so as to pump said secondfluid through said pump; and where said pump outlet is disposed in fluidcommunication with and concomitant to the outlet of said flow measuringcomponent.
 3. The dosing apparatus of claim 2 where said pump includes afirst and a second rotatable element situated in a comeshingrelationship.
 4. A dosing apparatus for mixing a first and other fluidsin a predetermined, volumetric relationship comprising: a flow measuringcomponent having an inlet in fluid communication with the first fluidand an outlet, where said flow measuring component further includesmeans which rotate at a selected number of revolutions when apredetermined amount of fluid is directed from the inlet to the outlet;means to translate the rotation of said component; a second fluiddisposed in fluid communication with the inlet of a fluid pump whichincludes a housing defining a fluid inlet and a fluid outlet, where saidpump is coupled to said translation means such that the rotation of therotational means actuates said fluid pump so as to pump said secondfluid through said pump; where said pump outlet is disposed in fluidcommunication with the outlet of said flow measuring component; andmeans to selectively divert a portion of the second solution pumpedthrough the pump outlet back to a fluid reservoir.
 5. The dosingapparatus of claim 2 where said flow measuring component and said fluidpump are integrally formed in a housing about a common drive shaft. 6.The dosing apparatus of claim 2 further including means to continuouslyremove deposits from the first and second rotatable element.
 7. A dosingapparatus for mixing a first and other fluids in a predetermined,volumetric relationship comprising: a flow measuring component having aninlet in fluid communication with the first fluid and an outlet, wheresaid flow measuring component further includes means which rotate at aselected number of revolutions when a predetermined amount of fluid isdirected from the inlet to the outlet; means to translate the rotationof said component; a second fluid disposed in fluid communication withthe inlet of a fluid pump which includes a housing defining a fluidinlet and a fluid outlet, where said pump is coupled to said translationmeans such that the rotation of the rotational means actuates said fluidpump so as to pump said second fluid through said pump; where said pumpoutlet is disposed in fluid communication with the outlet of said flowmeasuring component; and a second pump comprising a first and secondgear mounted between an inlet disposed in fluid communication which athird fluid and an outlet such that at least one of said first andsecond gears are also coupled to said translation means such that therotation of the rotational means urges a predetermined amount of thethird fluid from said inlet to said outlet.
 8. The dosing apparatus ofclaim 7 where the outlet of said second pump is coupled in fluidcommunication with the outlet of the flow measuring component through avalve to allow for selective diversion of at least a portion of thefluid pumped through said outlet to said reservoir.
 9. The dosingapparatus of claim 7 further including means to pressurize the secondpump.